A single‐step laser scribing process is used to pattern nanostructured electrodes on paper‐based devices. The facile and low‐cost technique eliminates the need for chemical reagents or controlled ...conditions. This process involves the use of a CO2 laser to pyrolyze the surface of the paperboard, producing a conductive porous non‐graphitizing carbon material composed of graphene sheets and composites with aluminosilicate nanoparticles. The new electrode material was extensively characterized, and it exhibits high conductivity and an enhanced active/geometric area ratio; it is thus well‐suited for electrochemical purposes. As a proof‐of‐concept, the devices were successfully employed for different analytical applications in the clinical, pharmaceutical, food, and forensic fields. The scalable and green fabrication method associated with the features of the new material is highly promising for the development of portable electrochemical devices.
Electrochemistry on paperboard: A simple, scalable fabrication of nanostructured electrochemical paper‐based analytical devices using a CO2 laser and paperboard is presented. The method does not require additional reagents or control of the fabrication environment.
Herein we demonstrate that adding single atoms of selected transition metals to graphitic carbon nitrides allows the tailoring of the electronic and chemical properties of these 2D nanomaterials, ...directly impacting their usage in photocatalysis. These single-atom photocatalysts were successfully prepared with Ni
2+
, Pt
2+
or Ru
3+
by cation exchange, using poly(heptazine imides) (PHI) as the 2D layered platform. Differences in photocatalytic performance for these metals were assessed using rhodamine-B (RhB) and methyl orange (MO) as model compounds for degradation. We have demonstrated that single atoms may either improve or impair the degradation of RhB and MO, depending on the proper matching of the net charge of these molecules and the surface potential of the catalyst, which in turn is responsive to the metal incorporated into the PHI nanostructures. Computer simulations demonstrated that even one transition metal cation caused dramatic changes in the electronic structure of PHI, especially regarding light absorption, which was extended all along the visible up to the near IR region. Besides introducing new quantum states, the metal atoms strongly polarized the molecular orbitals across the PHI and electrostatic fields arising from the electronic transitions became at least tenfold stronger. This simple proof of concept demonstrates that these new materials hold promise as tools for many important photocatalytic reactions that are strongly dependent on our ability to control surface charge and its polarization under illumination, such as H
2
evolution, CO
2
reduction and photooxidation in general.
Adding single metal atoms to graphitic carbon nitrides alters their properties, impacting their use in photocatalysis.
This living systematic review aims to summarize evidence on the prevalence of oral signs and symptoms in patients with COVID-19. The review was reported per the PRISMA checklist, and the literature ...search was conducted in 6 databases and in gray literature. Studies published in any language mentioning oral symptoms and signs in patients with COVID-19 were included. The risk of bias was assessed by the Joanna Briggs Institute appraisal tools. The certainty of evidence was evaluated through GRADE assessment. After a 2-step selection, 40 studies were included: 33 cross-sectional and 7 case reports. Overall, 10,228 patients (4,288 males, 5,770 females, and 170 unknown) from 19 countries were assessed. Gustatory impairment was the most common oral manifestation, with a prevalence of 45% (95% CI, 34% to 55%; I2 = 99%). The pooled eligible data for different taste disorders were 38% for dysgeusia and 35% for hypogeusia, while ageusia had a prevalence of 24%. Taste disorders were associated with COVID-19 (odds ratio OR, 12.68; 95% CI, 6.41 to 25.10; I2 = 63%; P < 0.00001), mild/moderate severity (OR, 2.09; 95% CI, 1.25 to 3.49; I2 = 66%; P = 0.005), and female patients (OR, 1.64; 95% CI, 1.23 to 2.17; I2 = 70%; P = 0.0007). Oral mucosal lesions presented multiple clinical aspects, including white and erythematous plaques, irregular ulcers, small blisters, petechiae, and desquamative gingivitis. Tongue, palate, lips, gingiva, and buccal mucosa were affected. In mild cases, oral mucosal lesions developed before or at the same time as the initial respiratory symptoms; however, in those who required medication and hospitalization, the lesions developed approximately 7 to 24 d after onset symptoms. Therefore, taste disorders may be common symptoms in patients with COVID-19 and should be considered in the scope of the disease’s onset and progression. Oral mucosal lesions are more likely to present as coinfections and secondary manifestations with multiple clinical aspects (PROSPERO CRD42020184468).
In order to probe a possible time variation of the fine-structure constant (
α
), we propose a new method based on Strong Gravitational Lensing and Type Ia Supernovae observations. By considering a ...class of runaway dilaton models, where
Δ
α
α
=
-
γ
ln
(
1
+
z
)
, we obtain constraints on
Δ
α
α
at the level
γ
∼
10
-
2
(
γ
captures the physical properties of the model). Since the data set covers the redshift range
0.075
≤
z
≤
2.2649
, the constraints derived here provide independent bounds on a possible time variation of
α
at low, intermediate and high redshifts.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Tuberculosis (TB) and depression act synergistically via social, behavioral, and biological mechanisms to magnify the burden of disease. Clinical depression is a common, under-recognized, yet ...treatable condition that, if comorbid with TB, is associated with increased morbidity, mortality,
community TB transmission, and drug resistance. Depression may increase risk of TB reactivation, contribute to disease progression, and/or inhibit the physiological response to anti-tuberculosis treatment because of poverty, undernutrition, immunosuppression, and/or negative coping behaviors,
including substance abuse. Tuberculous infection and/or disease reactivation may precipitate depression as a result of the inflammatory response and/or dysregulation of the hypothalamic-pituitary-adrenal axis. Clinical depression may also be triggered by TB-related stigma, exacerbating other
underlying social vulnerabilities, and/or may be attributed to the side effects of anti-tuberculosis treatment. Depression may negatively impact health behaviors such as diet, health care seeking, medication adherence, and/or treatment completion, posing a significant challenge for global
TB elimination. As several of the core symptoms of TB and depression overlap, depression often goes unrecognized in individuals with active TB, or is dismissed as a normative reaction to situational stress. We used evidence to reframe TB and depression comorbidity as the 'TB-depression
syndemic', and identified critical research gaps to further elucidate the underlying mechanisms. The World Health Organization's Global End TB Strategy calls for integrated patient-centered care and prevention linked to social protection and innovative research. It will require multidisciplinary
approaches that consider conditions such as TB and depression together, rather than as separate problems and diseases, to end the global TB epidemic.
Marine organisms are constituted by materials with a vast range of properties and characteristics that may justify their potential application within the biomedical field. Moreover, assuring the ...sustainable exploitation of natural marine resources, the valorisation of residues from marine origin, like those obtained from food processing, constitutes a highly interesting platform for development of novel biomaterials, with both economic and environmental benefits. In this perspective, an increasing number of different types of compounds are being isolated from aquatic organisms and transformed into profitable products for health applications, including controlled drug delivery and tissue engineering devices. This report reviews the work that is being developed on the isolation and characterisation of some polysaccharides, proteins, glycosaminoglycans and ceramics from marine raw materials. Emphasis is given to agar, alginates, carrageenans, chitin and chitosan, among other polysaccharides, collagen, glycosaminoglycans such as chondroitin sulphate, heparin and hyaluronic acid, calcium phosphorous compounds and biosilica. Finally, this report ends by reviewing the application of the previously mentioned materials on specific biomedical applications, in particular their participation on the development of controlled drug delivery systems and tissue engineering scaffolds.
Brazil nut tree (Bertholletia excelsa) is native of the Amazon rainforest. Brazil nuts are consumed worldwide and are known as the richest food source of selenium (Se). Yet, the reasoning for such Se ...contents is not well stablished. We evaluated the variation in Se concentration of Brazil nuts from Brazilian Amazon basin, as well as soil properties, including total Se concentration, of the soils sampled directly underneath the trees crown, aiming to investigate which soil properties influence Se accumulation in the nuts. The median Se concentration in Brazil nuts varied from 2.07 mg kg−1 (in Mato Grosso state) to 68.15 mg kg−1 (in Amazonas state). Therefore, depending on its origin, a single Brazil nut could provide from 11% (in the Mato Grosso state) up to 288% (in the Amazonas state) of the daily Se requirement for an adult man (70 μg). The total Se concentration in the soil also varied considerably, ranging from <65.76 to 625.91 μg kg−1, with highest Se concentrations being observed in soil samples from the state of Amazonas. Se accumulation in Brazil nuts generally increased in soils with higher total Se content, but decreased under acidic conditions in the soil. This indicates that, besides total soil Se concentration, soil acidity plays a major role in Se uptake by Brazil nut trees, possibly due to the importance of this soil property to Se retention in the soil.
•Not all Brazil nuts are selenium-rich.•Se levels in soils from Amazon region are below the toxic level.•Se content in Brazil nuts are influenced by soil pH.•Se contents in Brazil nuts varied widely among and within tree populations.
Non-relativistic quantum effects of the topology of the spacetime with the distortion of a vertical line into a vertical spiral on the harmonic oscillator are investigated. By searching for ...analytical solutions to the Schrödinger equation in this topological defect background, it is shown that the topology of the spacetime modifies the spectrum of energy of the harmonic oscillator. Besides, it is shown that there exists an Aharonov–Bohm-type effect for bound states.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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